Electrical devices comprise arrays of insulated wires extending from one electrical connector to another. The opposed ends of each wire may have electrically conductive terminals mechanically and electrically mounted thereto. The terminals typically comprise a forward mating portion and a rearward wire engaging portion. The configuration of terminals varies widely depending upon the particular intended use for the terminal. However, the rearward wire engaging portion of most terminals is crimpable into electrical and mechanical engagement with the conductors of a wire. Some terminals are constructed to be mounted to an insulated wire, and the rearward wire engaging portions of such terminals are constructed to displace or pierce the insulation to achieve the required electrical connection with the conductor of the wire. With other terminals, a selected amount of insulation must be stripped from the end of the wire to enable the rearward end of the terminal to be crimped directly to the exposed conductor for achieving both mechanical and electrical connection therewith.
Electrical terminals typically are stamped and/or formed from a continuous strip of metal. A portion of the original strip is retained as a carrier strip for storing and transporting the terminals to the location at which the terminals are mounted to the wires. A plurality of such terminals and their carrier strip may be mounted to a reel for storage and shipment to a location where the crimp operation of terminating the terminals to the wires can be performed. Strips of terminals, however, are not well suited to being stored in tightly nested coiled relationship with one another. Thus, a continuous strip of interleaf material, such as paper or foam, may be wound with the strip of terminals to define alternate helical layers of interleaf and terminals. The interleaf functions to prevent adjacent wound layers of terminals from being entangled with one another and ensures that the terminals can be conveniently and reliably unwound from the reel. A typical reel of this type may be 24 inches in diameter and may contain thousands of terminals.
The strip of terminals typically will be delivered to a terminating press which is operative to crimp the rearward end of each terminal onto a wire and to simultaneously separate the terminal from its carrier strip. These crimping operations typically are carried out either manually or with an automated apparatus that is closely supervised by an operator. In a typical crimping operation a reel of terminals will be mounted to a nonrotatable shaft. A retainer plate may be mounted to the prior art shaft to retain the reel thereon. The retainer may incidentally exert a friction force against the rotating reel. However, the friction exerted against the reel by the prior art apparatus is not controllable.
The operator will feed the strip of terminals into a terminating press while taking care to manually separate the interleaf material from the terminals advancing into the press. Although most terminating presses index the strip of terminals automatically, the operator periodically must tear portions of accumulated interleaf material from the advancing strip for discarding into an appropriate trash receptacle. The operator also either feeds or oversees the feeding of wire into the terminating press. Depending upon the particular terminals and crimping process being employed, the wires may first be processed by removing a selected length of insulation therefrom.
The terminating press is operative to index the strip of terminals into a position where a terminal is aligned to receive the end of a processed wire. The wire end is urged into proximity to the terminal on this prior art terminating press, and the press is operated to crimp the terminal onto the wire. The terminating press completes its cyclical operation enabling the terminated wire to be removed therefrom and indexing the strip of terminals again to move the next sequential terminal into position to receive a wire.
As the number of terminals on the reel decreases, the operator employing the prior art apparatus may attempt to decrease the frictional force exerted on the reel by the retainer plate. In particular, the frictional forces exerted by the retainer plate on the reel should be fairly high when the reel is fully loaded to prevent overrunning of the reel. However, these high forces will make it difficult to pull terminals from the reel as the reel approaches its empty condition. Excessive dereeling tension can either break the carrier strip or prevent proper indexing. It is difficult for the operator of the prior art apparatus to precisely predict the required variations in the frictional forces on the reel. Therefore, accurate and timely adjustments to the retainer plate of the prior art apparatus are unlikely.
The prior art has included various attempts to reduce the amount of operator work and supervision required for harnessing work. However, these prior art attempts at automation have not been completely successful in replacing the various steps that had been carried out by the human operator. For example, the prior art attempts to automate the terminal dereeling and crimp work have not adequately accounted for the interleaf material that is required to prevent entanglement of terminals on the reel. In particular, the interleaf material would have a tendency to entangle with, jam and damage the terminating press.
These prior art attempts at automation also could not account for the amount of tension force required to pull the terminal strip from the reel. In particular, the prior art attempts at automation would result in too low a friction force on a nearly full reel resulting in overrunning of the reel and excessive feeding of terminals into a position where the terminals could be damaged. Alternatively, the prior art automated terminal feeding apparatus would result in excessively high tension to pull the strip of terminals from a nearly empty reel, thereby creating the possibility of damage to the strip before all of the terminals thereon have been properly mounted to wire leads, and/or improper indexing of the strip.
The operator of the less automated prior art devices fullfilled an important function of almost immediately identifying jams or other malfunctions such as multiple terminations to a single wire or no terminations to a wire. The operator of the typical prior art apparatus could immediately stop operation of the apparatus, correct the problem and recommence the termination procedure. However, the more fully automated prior art devices did not adequately replace this important human operator function. Thus, the prior art automated terminal feed apparatus would continue to feed terminals into a crimp press in spite of a jam thereby yielding multiple terminations. These plural terminations could damage the expensive tooling on the terminating press and would result in extensive costly down-time.
Typical examples of prior art attempts to automate the terminal feeding and harnessing work include: U.S. Pat No. 4,043,032, which issued to Spangler on Aug. 23, 1977; U.S. Pat. No. 4,489,871, which issued to Bakermans et al. on Dec. 25, 1984; U.S. Pat. No. 4,691,437, which issued to Vaglini on Sept. 8, 1987; U.S. Pat. No. 4,403,407, which issued to Mazzola on Sept. 13, 1983; U.S. Pat. No. 4,631,823, which issued to Collier on Dec. 30, 1986; U.S. Pat. No. 3,548,479, which issued to Netta on Dec. 22, 1970; and, U.S. Pat. No. 4,718,160, which issued to Bulanda on Jan. 12, 1988.
In view of the above, it is an object of the subject invention to provide an automated terminal dereeling apparatus.
It is another object of the subject invention to provide a terminal dereeling apparatus that can be used with a terminal crimp press, a wire processor and/or other apparatus for performing harness work on a wire.
It is a further object of the subject invention to provide a terminal dereeling apparatus with means for accumulating the interleaf strip disposed between adjacent coils of the terminals and carrier strip on the reel.
An additional object of the subject invention is to provide a terminal dereeling apparatus that is operative to smoothly and continuously feed terminals from the beginning to the ending positions of the strip of terminals wound onto the reel.
Yet another object of the subject invention is to provide a terminal dereeling apparatus which is operative to sense the proper indexing of terminals into the terminating press.
It is still an additional object of the subject invention to provide a terminal dereeling apparatus which is operative to discontinue wire processing and terminal crimping in response to a sensed improper indexing of terminals into the terminating press.